Railway-traffic-controlling apparatus



'July 29, 1930. s, LQOMIS ET AL 1,771,715

RAILWAY TRAFFIC CONTROLLING APPARATUS Filed May 15, 1928 4 Sheets-Sheetl July 29, 1930. H, s, Looms ET AL 1,771,715

RAILWAY TRAFFIC CONTROLLING APPARATUS Filed May 15, 1928 4 Sheets-Sheet2 R N m A i O INVENTOR S mam 1. f

July 29 1930. I s, LQQMISEF AL 7 1,771,715

RAILWAY TRAFFIC CONTROLLING APPARATUS Filed May 15', 1928 4 Sheets-Sheeta Source of Fluid Pressure Brake Pzjoe INVENTORSI y 1930. H. s. LOOMISET AL 1,771,715

RAILWAY TRAFFIC CONTROLLING APPARATUS Filed May- 15, 1928 4 Sheets-Sheet4 v m mg w Em w Patented July 29, 1930 V UN1TED5TATE5 P ENTLQFFICEHAROLD s.- noolvrrs, on ,wiLxmsncne, nn HOWARD A. THomrsoN, on EDGEWOOD;BOROUGH, PENNSYLVANIA; ASSIGNORS TO-THE UNION swxrcnk; SIGNAL M:-

PANY, OF SWISSVALE} PENNSYLVANIA,

A- CORPORATION OF PENNSYLVANIA RAiCLWAY TBAFFZC-CQNTRQLLING Hu musApplication fil afivm 15,

Our invention relates to railway trafiiccontrolling epp'eretiis, andparticularly to epparatus of the type comprislng train carried governingimeans' controlled by devices cet ed at'interv-als along the trackway;

One featnreof-oi'ir intention isthe pro vision in apparatus '01: thetypedescribed of train carried governing means which is eftectiveattiinestocause a service application; of the brakes Which can be released bythe engineman only after the expiration of a time intervalwhich is ofsuch length as toin-I su'rcthat the train speed has been reduced to acomparativelylow value. 1

Another feature of our'invention ,is the provision of means forpreventing anhuto V nlatic application of the brakes, even; under unsafetraffic conditionsyifthe speedof the train is below the valuefroniivhich the serv ice applicationcen bring thetrein to a full stopshort of the hazard which render ing trafiic conditionsiinsai'e. i

Other features andhdvantltges of our partly dia'grammatio and partly insection,

showing one form of train carried governing means suitable'torcooperation with the track- Waynpparatusillustratednn Figs. 1 and 2 andalsosinbodying our invention. F

. is ediagra'n'imatic View showingin modified i Fig. 11,andelsoeinhodying onr invent-ion.

iorin a portionef the apparatus shown in Similar reiierencechzira'ctersrcfer to similar parts in each or the severalVieWs.

Referring first to Figs- 1 and 2, the reference jcheracters l and 1designate the" rails of a e etch of railway track over; which trafjficnorn elly moves ingthei d 'ection;indicat-; ed: by ithe errow."ilhese-raxds are I divided, 1' inc-ens insulatedjointsfi to formpe pluf ialitj of successive track sections AB,

vention will appear fas the description; pro

7 tion islprovided Witll'a trackjciricnit compris r lngithe secondaryofatrack transformer 4, e i 'ei f tr k m y e P ima y of.

1928. see-e1. .Nol z'zspcs.

B,C C D; D 43, end IE- F. Each track section is provided withaIsourceoftreckY circuit current here shown as a transformer designatedby the referenceclmracter with an exponentcorresponding to the location"and hztvingits secondary connected j a x 5 the rails: tidjecent the exitthesection. The primary of eachtrack'transformer is constantlysupnliedwith alternating current from a suitebl e'source of energy such as itlinetransfmmer designated by the reference character 7 with an exponent;corresponding tofthe location and siipplied with energy' from a ralternator M overline Wires3. In

' order to simplify the drewingwe have ornitj 5 ted the wireswhichconnectthefterminals of I the secondary of the several, linej transformers Wrththeapparetus to which these seepedi pp y ner y; et r i iiml bch]? 1 line transformer'seconderya re design ated the referencecharacters- X 'andjYfW-itli ex l ponents corresponding to thelocatiomend similar reference characters are applied ft'o j theterminals ofth'e various circuits; v Each track section u x v is alsoprovided a track relay designated by the referencecher actor B with gn-exponent corresponding fo the location and connected across the.rziils adpicent theentran'ce endofthelsection. one

rail 1 of each section is providcd with an additionalirr'isulated.joint,2? at ap'oin't in the rear of'the exit end of thesection. :The primary of a transformer 5 is connected across L eachsuchjoint 2 andthe secondary ofeach -such transformer 5 is c 0nnectec1through a ignzttedbythe reference charz cter J with an appropriatedistinguishing exponent. Iti v W1l1'be plain, therefore, that eachtracksec:

a transformer 5, and the rails' of the sect-ion;

andthfe tissociated relay J is also energized. j

: W-Yhen enter s tliei sectiong the track imm tel b me i en r iz u thereley J for, that section remains "en'epq gized until the train passesinsulated joint 2* whereupon relay J opens and remains open until thetrain has passed out of the section.

Each section is also provided with a polarized home. relay and a homerepeater relay designated by the reference characters H and terininalsIXand Y of'transformer 7 A and; when the circuit just tracedlis; closed,relay.

. Hf i s ,.energiz ed infone direction, which I L from a trainsformer 19the primaryof which. is constantly cqnnected. with terminals X3 and Y ofline transformer? 3. Oiiecircuit. for relay Q? may. be tracedfroin theupper will calljthe normal directiodsothat its con! tacts are swung; to(the. left. \Nhen rel G? is. 'de-energized, however, the lower terminalof thesecondary'of transformer 12 is connectedwith wire- 15,, Overbacki.contact. l l of relay, GB. and. under .these conditions, therel-.

atiye q'larity of, the current supplied to. the windiiig 8] of relay His reversedso. that the relay isenergized in its reverse direction toswingitscontactsto the right, When relay His energizedin eitherits,normal, or reverse direction, current is supplied, to relay G, over cntactBL of relayH so that relay G is energized. Vltheiilrelay H?isde-energiaed, however, the circuit f91; r.e'1ay; G is nterrup he att'elay. 15 def energized. The circuits fQreach, of, the; re-

maining'relaysH and G aresimilar to those; i l tdes r bed fer re ays. HtndG. andwill e idr teodfronithe awing .Wi hP-u? 1- ie je p anat en.

pel r d. d st n l y. de igna ed? by t referencejchara'cter Q with} asuitable exponent andcomp'risingtwo windingslO andjl'l,

one of which, v 11, is constantly supplied. with alternating currentfrom terminals Xff and. Y4." 'Assoc'iatediwith' each distant relay Q, isa distantjrepeater relay designated by the. reference character P withan appropriate ex ponent 1 Referring particularly, ltoflrelay. .QA,

this relay isfa't times suppliedwith energy.

terminal of the secondaryoftransformer. 19 through wire 132,.frontcontact, 21 of relay Pl, wire 22,:front c0ntacti23j of relay Ga,wire 24, normal contact 25 ofrelay H wire 26, frontcontact' 27 of relayG4, wire 28,

winding 1Oof relayQ ancient-29 to the midpoint -3of'-' the secondary"of" transformer 19}? w en; the circuit j ust; tracedis closed,

Eac r ck sect n. is else prov ded wit 2- relay Q is energized in thenormal direction to swing its contacts to the left. When relay P isde-energized, however, the lower terminal of the secondary oftransformer 19 is connected with wire 22, over wire 30 and back contact21 of relay P and under these conditions the polarity of the currentsupplied to relay Q is such that the relay is energized. in its reversedirection to swing its contacts to the right. Relay P is energized whenrelay Q is energized in either direction but is de-energized when relayQ is de-energized. The remaining relays Q and P are provided withcircuits similar to those just described for Q and'P Associated witheach section is a governingdevice designated by the reference characterL with a suitable. exponent. and arrangedtocooperate with train carriedgoverning means as will'be described. in detail hereinafter. Eachof thedevices L is biased to an effective position (see L but maybe moved toan, ineffective position (see-L by means of. operating mechanism notshown in the drawing. Each device L also comprises a contact 51 which isarranged to be closed when the device occupies its ineffectiveposition.but to be open whenthe device occupies its effective position. One formof device operating in the mannerdescribed isdisclosed and claimedinLetters Patent of the United StatesNo.,1,59 1,988, issued July13, 1926,

to VVillianlG. MclVhirter, for railway traffic contnollingapparatus. 7

Each of thedevices L. is provided with a main.operatingv circuitand anumber ofauxiliary circuits. Referring] particularly to device. L themain circuit for this device maybe tracedfrom. terminal X overv frontcontact 33 of relay R wire 34, front contact 35 of. relay G wirer36,normal contact 37 of. relayl-I-f, wire 38, front contact 39 of rela y Pwire 40, normal contact 41 of relay 4, and WiresAQ, 43, 44, 45, 46,47,and 48, through the operating mechanismof device L4 to terminal Y When.this circuit is closed the device. L occupiesits ineffective positionbut;if the circuit is, for any reason interrupted, the device movestoits effective position. i

Associated with each section isa trackway signal which in the form shownis a light The middle arm m of 'each signal comprises three red units,two'yellow units, and one green unit, and the bottom arm on of eachsignal comprises two red units and one green unit; 1 Each signals iscontrolled in part by For example,

is open; Underthese conditions, the main circuit for device L is open sothat this device OCCLlPlGSJtSGfiBClJIVG conditionr Since a front contact59 of relay R is open, the cir cuit for light-out relay K is open andthis relay is deenergized. Under these conditions,-current flows fromterminal X over back contact 53 of relayK wire 54,1a red unit of themiddle arm of signal" S wire 55, a ma unitof the bottom arm 5, wires 56and 57, a red unit of thetop arm t-of signal S and wire 58 toterminal YThe indication presented by the signal under these conditionsisthree-red lights in a vertical row.

The current "supplied to section EF- transformer l energizes relay Jland relay R but the circuitfor relay H is open at front contact 16ofrelay R so that relay H is tie-energized. Relays *RQ and P are alsodc-energized. The main circuit for device L is'therefore open and thisdevice occupies its efiectivexposition. Under the conditions justdescribed, current flows from terminal X over front'contact 59 of relayR wire 60, winding of relay K wire 61,

back contact 63 of relay G wire 64,21 yellow unit of middle arm m ofsignal S w'ires65 and 66, aired unit of the bottom arm 5, wires 67 and68*, a red unit of-thetop arm 15, and wire 69 to terminal Y Theaspect-now displayed by signal S is a red light over a yellow light overa red light. i

Relays J and R associated with section DE are'both energized andsince'relay G is de-energized, current is now supplied to relay H toenergize this relay in-its reverse direction. Relay G is thereforeenergized but relays Q and P are open. The main operating circuit fordevices L is open and: the device occupies its eife'ctive posltionp Theaspect now displayed'by signal SP com prises a red light over a yellowlight over a iial X, over front contact 59 of' relay R \vireGO, windingof relay KP, wire 61, front contact 63 of relayG wire 62, reversecontact *(0 ofrelay H, wire 71, a yellow unit ofv the middle arm mofsignal ghfwire 72, a greenunit of the bottom arm 6, Wire 68, a

top arm t and wire to red unit of theterminal Y. A v 1 4 Referring now:to section C'D,jrelaysJ and R are both energized. Since relay. G isenergizedfihe current supplied to relay H position.

"reen light, the circuit passing from termi-- energizes this relayinitsinormal direction and relay G is energized but relays Q and.

P arebothde-energized. Under these conditlons the'circuit forv deviceLis open so that this device (occupies its effective position. Thecircuit for signal S underthese conditions may be traced from terminalXover-front contact,59 of relay Rfl wire 60,

Winding of relay KC, wire 61, front 3 contact 63 of rela G wire 62normal contact 70' of relay H wire 73, back contact 74 of relay 1?, wire75, a red unit of the middle arm m of sig11al"S ,w1res 76 and 77, ayellow unit of the top arm t,wires 78 and 79; a red unit of the bottomarm-3b, and wire 80 to terminal Y. The aspect displayed by signal Sunder these conditions over red over red.

Relays R and J 'are b oth energizedand:

relay H is energized in its normaldireotion.

therefore isyellow Relay G is also energized. sincefrelay H isenergizedfin its normal direction to close contact 25- and since frontcontact 23 of relay G is also closedpa circuit is completed for relay QRelay P is tie-energized, however, so that the current supplied torelay" Q energizesthis relay in its reverse direction. Relay P isenergized,-but the main circuit for device L is open 'and'this deviceoccupies "its effective a position. i With the apparasusat pointB in thecondition in which it is illustrated in the drawing, the signalsdisplays an: indication comprising yellow over green over red,thezsignal circuit passing from terminal X over. front contact 59 i ofrelay R wire 60, Windingv offrelaly'K wire" 61, front: contact 63 ofrelay G wire I62,

normal contact 70 of rela 'H wirel73 front contact 74 ofrelayiP wire 81,reverse conl tact 82 of relay Q wire 83, a green unit of" middle arm mof signal S wire 77; a yellow unit oftop arm t, wires 7 8 and 79, ;a redunit of bottom arm Z), and wire 80 to terminal Y Relays R rand- Jassociated "with section AfB are energized and relay'H 1s energized inthe normal direction. JRelay Gr is therefore picked up. ".Since relay Pis now energized relay Qfi 11s energized 1n the nor-1 mal directlon andrelay P isfalso energized;

It will be seen, therefore, thattheflmaincircuit first traced for deviceL is now closed and that this device occupiesits ineffectiveFurthermore, a ;c1rcu1t is nowclosed for signalSf from terminalgX overfront contact 59of relay R wirezfiO, wind-Q ing of relay-K -ywire 61,front contact 63 of relay GA, wire 62. normal contact 70 of relay H wire73, front contact 74 of relay P I WireSl, normalcontact82 of relay,Q,wire ea, unit-of theitoparm tof signal S, wire85, red unit of themiddlearm m, wires 5 5 86and79, a red unit of the bottomarmjbgand WireSOto terminalgY The aspect: displayed 1 Ot er-red? V. v a

describing-the circuits of the various signals, we have applied the samereference .characters to correspondingparts at each location tofacilitateflcomparison of the signal; circuits at the several locations.

ditions a burned out light unit :will cause the corresponding signal todisplay the most restrictive signal indication. V

The trackway apparatus illustrated in Figs. 1 and 2 is suitable forcooperation with train carried governing means which is responsive tothe positionsof the devices L located in the trackway. One for-mot train.-carried apparatus which will cooperate in this manner is illustratedin Fig. 3. In this view the reference character N designates anengine'mans brake valve of the usual and well known form for controllingthe usual automatic brake applying apparatus on the train through themedium of the brake pipe 104. Associated with the valve N is anapplication slideva'lve comprising a piston 111 which is urged to anupper position by a ,f spring 113. Fluid under pressure, usually air, isconstantly supplie'd'to'the upper side of. the piston lllfrom asourceof'fiuid prev surenotshown in the drawing through" pipes 87 and110. Pressure is also supplied to the I lowerside of piston 111, througha restricted orifice 112 in the piston. 1 The combined forces of spring113 and the pressure on the lower side ofpiston 111 normally hold thispiston, and the slide valve controlled therei by, in their upperpositions, in which they are illustrated-in the drawing. Under theseconditions, fluid pressure is supplied to the brake-pipe from pipe 87,through pipe 88, the

usualfeedvalve 89, pipe 90, port 91 in the enginemans brake valve, pipe101, port 102 in the application slide valve, and pipe 103 to brake'pipe104. The brake-pipe 104 isalso connected to chamber 97 beneath the usualequalizing valve 98 V The chamber 95 above therefore, the equalizingreservoir 96 is the equalizing valve 98 is constantly connected with anequalizing reservoir 96, and chamber 95'and reservoir 96 are both connected through pipe 94, port 93 in the ap plication slide valve, pipe92, and port 91 with pipe 90. ,Under normal conditions,

charged-and the same pressure exists on both sides-oftheequalizing valve98 so that valve 99is closed. A reduction limiting reservoir i106 isconnected, through pipe 107 and port 108 with atmosphere at port 109. Apipe 114 is constantly-connected with the chamber beneath the piston111. When this pipe is vented to atmosphere, therefore, the pressureabove the piston 111 over-balances the pressurebeneath this piston andmoves the piston to a'lower position. WVhen this occurs, the elosingofport 102 disconnects the brakepipe from pipe 101. Furthermore, port 93now'connects the equalizing reservoir with the reduction limitingreservoir and blanks port 109. The pressure in the equalizing 'reservoiris thereforereduced and the equalizing valve 98 moves upwardly to venthe brake pipe 104 through the restricted orifice 100, until thepressures on the two sides of the piston are equal, whereupon the valvereturns toits original position to prev'entfurther bleeding of the brakepipe.

When the piston 111 is. in its lower position, port 116 connects pipe114 through pipe 115 and port 116, pipe 117, and port 118 of theengineinaus brakevalve with atmosphere at pipe 119. The port 118 is openat all times except when the enginemans brake valve occupies the lapposition. It follows that after the piston 111 has moved to its lowerposition to cause a brake application, the piston'remains in its lowerposition until the valve N has beenmoved to the lap position. The partsare so proportioned thatwhen the piston 111 moves to its lower position,the reduction'in brake'pipe pressure is such as to cause a serviceapplication of the brakes.

It should be noted that when the piston 111 occupicsits lower positionit is impossible to charge the brake pipe through the enginemans'brakevalve because pipe 92 and pipe 101 are both blanked at the slide valvecontrolled by the piston.

Pipe 114, which controls the piston 111, is in turn controlled by avalve device comprising a main valve 121 having its lower endterminatingin a piston 123 and biased to the position inwhich it is shown in thedrawing by a spring 122. l/Vhen' the valve is in this position, chamber126 is discon nected from a passage 133 which leads to atmosphere. Thevalve 121 is hollow, and its lower end contains a pilot valve 128 whichis normallyheld-closed'by a spring 127. The chamber 126 is connectedwith a reservoir 124 through holes 125 drilled in the valve 121,and thechamber 126 is also connected, through pipe 141 with a reservoir 120 andpipe 114. Under normal conditions, then, reservoir. 120 and reservoir,124and, chamber 126 are allcharged with fluid pressure which isadmitted'to pipe114through restricted orifice 112 in piston111. Underthese conditions, the spring 122 holdsthe valve 121 in its lowerposition and valve 128 is also closed. 'The ,reference character 129"designates a plunger which is arranged to be moved upwardly when thetrain passes a trackway de-' i,

WVhenthe plunger'129 is moved upwardly,it engages the lower end of thepilot valve 128,

moving this valve against the bias of spring 127', andndmitting air fromreservoir 124 through thehollow stem'of valve 121 to the chamber130below piston 123. As a result, the piston123, and valve 121carriedthereby,

-are forcednupwardly against the bias of spring 1122.

This movement of valve 121 closes holes 125 and traps the pressure inreservoir 124:. and chamber 130 thereby holding the piston 123 in itsupper position. The

piston 123. carries a pivoted pawl'131 which is effective when thepiston123 is in its upper position tohold the pilot valve 128 open.WVhen valve 121 is moved upwardly, chamber 126 is connected withatmosphere through passage 1553, thereby venting pipe 141 toatmosphere,and emptying reservoir 120 and the chamberbeneathpiston 111 of theapplication slidevalve. This operation'causes a service application of.the brakes in the manner already described. The pressure in reservoir124 which is trapped by the movement of valve'121 upwardlyto close holes125, holds thepiston 123 in its upper position long enough to'insurethat the reservoir 120 is completely discharged. The pressure trappedinreservoir 12 1 gradually leaks oil, however, through the guides of thevalve 121 and the pilot valve 128,- andafter theexpiration of i a timeinterval, spring 122again restores the valve 121 to the position inwhich it is illus- V trated in the drawing, thereby allowing valve 128to close. If, now the engineman moves valve N to the lap position,pressure from pipe 110 passes through the restricted orifice 112 inpiston 111 and gradually charges reservoirs120 and 12 1. After theexpiration of a time interval, such for example, as 15 seconds, thepressure below piston 111 is increased to a sufficient value, to permitthis pressure plus the effect of spring 113 to restore the piston 111 tothe position in which it is illustrated in the drawing therebyconnecting the reduction limiting reservoir 106 to atmosphere, andres-charging the :brake pipe to itsoriginal value.

Itwilllbe plain from the foregoing that when. the train passes atrackwaydevice. L

in its effective position, the operation of plunger129 initiates aservice application of the brakesand that this automatic application canbe released only after the expiration of thetime interval requiredtocharge reser= voir120 and return piston 111 to itsupper position. If,prior to the restoration of the piston .111 to its upper position, thetrain passes a second trackway device L in its effective position, theplunger 129 is again raised, and again ventsthe reservoir 120 toatmosphere sogthat the time interval requiredlto charge reservoir-120 isre established. follows that thebrakes canbe released only at theexpiration of the full time interval of 15seconds after t-hela'stactuation of the valve 128 by a trackway device L.

Referring now alsozto FigsJl and 2,;we

-will assume thata train providediwiththe apparatus illustrated in Fig.3 passes through the stretch of track shownin Figs. 1 and 2. WVhen thistrain passes device L the plunger 129 is notoperated becausethisdeviceis in its ineffective position. I When the train enterssection LA-B, relay R becoines de-energized, thereby causing thede-energizationofrelays H G Q}, andP andcausing signal S to display astop indicationsimilar to that illustrated in the drawing at signal S,that is", red over red over red. Furthermore, the circuit for device Lis now interrupted and with only'the apparatusthus far described thisdevice would move to'its efiective position. With systems ofthe typedescribed it is not unusual to operate trains consisting of two or morecars each provided with apparatus similar to that illustratedin Fig. 3."Under theseconditions it would be undesirable to have the device Lcooperate with plunger 129 on each of-the cars except the first car, andwe therefore provide means; for holding the device Lin its ineffectiveposition until the rear of the train haspassed the device, providing thedevicewas in its ineffective position when the train approached thedevice. This is accomplished by means of an auxiliary circuit for eachdevice L controlled by the associated relay J. For example, when thetrain passed joint 2 in approaching point A, relay J Abecamefde-energized. Since decontact 51 was closed anda circuitwas'closed for device L from terminalX over" back contact 19, of relayJ, wire 50, contact 51,

wires 52 and 48, and operating mechanism of device L to terminal Y VVhenthe train enters section A 13," therefore, the main operating circuitfor device L isopen butthe device is held in its inefiective position byvirtue of the circuit just traced, until the rear of the train haspassed out of the section to the left of point A.) When thetrain passespoint B, devicegL which nowoccupies its effective position, liftsplunger l29 *onthe' train and initiates aserviceapplication ofthebrakes. Furthermore, the plunger 129 issuecessively operated as thetrain passes devices L2, L ,and L I The lengths of the track sec tions'are'so chosen and the severity ofthe service application. of the brakescaused on board the train is so regulated thata't-rain travelling at themaximum permissive speed a will be brought to a full stop. beiorereaching pointF. Furthermore, thetraincarried apparatus issol proportionthat ii -attain travelling atthe maximum speed passes point Bshould'incura brakeapplication, the time interval required to releasethe brakes, will be so long that successive operations of theapplication of the brakes Will-have so'deceleratedthe train that thetime required to vcharge the reservoir 120 will be consumed before thetrain reachespoint F The engineman may then release the brakes by movinghis valve Nto the lap position. Butunder these conditions, since thebrake application has, endured since the train passed point B, the trainspeed willbe so reduced that it will be safe to proceed-at the low speedatwhich the train will then be operating. I

With only the apparatus thus far described, it will. be seen thatno-matter how low the speed of the train, the train will-receive anautomatic application ofthe brakes assoon as it proceeds within fourtracksections' of a hazard here represented by train Z. In systems whichmust accommodate-a large volume of traflic, this feature is undesirable,because it increases the headway, or'minimum safe distance betweentrains. For this reason we have provided means for each sectioneffective when the main operating circuit for the associated trackdevice L is open, to move the device to its ineffective positionup'on'the approach of a train moving ata speedless than that of themaximum speed fro-mwhich a'continued service brake application can bringthe train to a full stop short of the hazard which has caused-the unsafetralfic conditions that opened the main operating circuit for the deviceL.

In order to accomplish these results, we provide each section with fourtiming relays designated by reference characters '1, U, V, and'W,respectively, with exponents corresponding to the location andcontrolled in parallel-by a backcontact 136 of the associated relay J.All of the timing relays are therefore normally de-energized but when atrain passes the point of connection of transformer 5 to de-en'ergizethe relay J, the corresponding timing relays are all'energi'zed. All ofthe timing relays are slow acting, however,

so that an interval of time elapses after the de-energization of relay Jbefore these relays elose their front contacts; Furthermore, the fourtiming relays for each section require different times for theiroperation so that the I relays close their contacts insuccession: The

parts are so1.'proportioned*that the time required for theoperation ofeach relay T is slightly lessthan that required-for a train travellingat some lowspeed, such as'1'0 mil'es per-hour, to travel-from theinsulatedjoint 2' to the adjacent trackway device-L. Insimilar manner,the time interval required for each relay U to close its front contactis slightly less than the time required for a train travelling atasomewhat higher speed,

example, as miles such as 20 miles per hour, to traverse the samedistance. In similar manner, relays V andVV at each locationare'adjusted to. correspond to different high speeds, such for per hourand miles perhour, respectively. 1

Assuming, now,that the train passing device L is travelling at themaximunrpermissive speed, such for example as miles per hour, this tramWlll lncur a service application of the brakes at point B and-therepeated operation of plunger 129v by devices L L and L will cause thisapplication of the brakes topersist to bring the train to a stop beforeit reaches point F. e will next assume, however, that the trainapproaching point B is traveling at a lower speed, such for example, as35 miles per hour. :Under these conditions, the timingrelay VV becomesenergized before the train reaches point B and a clrcult 1s then closedfrom terminal X over front contact 33 of relay RB, wire 34, frontcontact 35 of relay G wire 36, normal contact 37 of relay H wire 38,front contact 39 of relay P wire 40, reverse contact 41 of relay Q Wire142, front contact 143 of relay WV wires 14 4, 43, 44, 45, 46, '47, 48,and

. operating mechanism of device L to terminal Y It will be plain,therefore, that-even though traffic conditions in advance are unsafe,the'device L will be moved to its ineffective position to preventan'application of the brakes if the speed .of the train is be low apredetermined safe speed.

In similar manner,'when the train passes device L this device will beheld in its ineffective position if the train speed is below a safevalue, but this value is now determined by the timing of relay V thecircuit for device L passing from terminal X through front contact 33 ofrelay R wire 34, front contact 35 'of relay G wire 36, normal contact 37of relayH wire 38, back contact 39 of relay P wire 145, front contact146 of-relay V wire 147, 44, 45, 46, 47 and 48, and operating mechanismof device'L to terminal Y It will therefore be plain that if the trainapproaching point C is travelling at a speed below 30 miles per hour thedevice'L will be moved to its ineffective position be fore the trainpasses this device so that no automatic application of the brakeswillresult. In similarinanner, a circuit is'prepared at point-D fromterminal X over front contact 33 of relay R wire 34, front contact 35 ofrelay G wire 36, reverse contact 37 of relay H ,'wire 160, front contact148 of relay U .-wires 45, 46, 47, and 48, and operating mechanism ofdevice L to terminal Y This circuit is closed when relay U beceme'senergized. This'can, of course, happen only if the speed of the trainapproaching point D is below the value for which the'relay U is pointsin the section.

point E is moving at a speed belowthe value determined by timing relay Tthe energization of this relay completes a circuit for the device Lincluding front contact 33 ofrelay R back contact 35 of relay G andfront contact 149 Off relay T It will t rere'fore be plainthat at eachlocation the tra clrway device L is so controlled that under unsafetratlic conditions, a train approaching the hazard whichcauses unsafetraliicconditions may proceed Without incurring anapplication of thebrakesto a point located at, a distance in rear of this hazard whichdepends upon the speed of, the train and is equal to the distancerequired to bring the train to a full stop short of the obstruc tion. a.i a I y [By making the maximum length of each section only acomparatively small partof themaximum braking distance and by initiatingthe automatic application at several sections in rear of an occupiedsection, we have produced a system which permits a material reduction inthe headway required for the safe operation of trains.

Under some conditions of operation it may be desirableto ar 'ange theapparatus to en sure that the speed of the train does not exceed somemaximum value. This may be accomplished with the apparatus shown in Fig.4. In this view the lining relay T is controlled by relayd in suchmanner that relay T becomes energized when a train is a; preaching pointB if the train is travellingat a speed below the maximum permissivespeed. With this arrangement, it traific conditions in advance are sale,a circuit is completed for the operating mechanism of device L overfront contact 150 oi relay P normal con tact 1.51 of relay Q andrlirontcontact 1520f relay T so that the device is moved to its ineffectiveposition before the train passes the device. If, however, the speed ofthe train exceeds the maximum permissive speed for which the timingrelay T? is adjusted, the device L will be in its effective positionwhen the train passes the device and an automatic application of thebrakeswill result. Furthermore, an automatic application of the brakeswill result if a train passes point B when traffic conditions in advanceare unsafe, the control of the variousrelays located at point B beingthe same as has already been described in connection with Fig, 1;

It is also sometimes desirable to arrange the apparatus to ensure that atrain moving through a section immediately in rear of an occupiedsection shall not proceed at speeds greater than a predetermined lowvalue. To accomplish this result, the section A'B is provided, in Fig.4, with two relays J and J receiving energy from transformers 5 and 5connected across insulated joints 2 at spaced 7 Relay J controls atiming relay T Relay J 2 controls a timing relayT". The two timingrelaysT andJIl conrtol the trackway devices L and L which are similar to theother devices .L liereinbefore described. Device L? is normally held inits inefiectiveposition byvirtue f a cir-' tions, then, devices L andLare at alltimes held their ineffective position: fWhenthe sect ontotheright olrpoint B is occupied, however, relay B asdeenerginecl andthe circuits just described} for trackway devices L and L are then open.\Vhen timing relay T is energized, current; is supplied to device L overitslrontlcontact 155 and the parts are so proport oned andlarranged thatif a trainv approaching device L is moving-at a speed below apredeterminedlow value, relay T will become energized after this trainpasses the insulated joint 2? associated with relay J? and before thetrain reaches device L As a result, the device iwillgbemoved to itsineffective position and noautomatic ap; plication of the brakes willresult. Further? morethe closingof relay-Th completes a circuit fordevice L including front contact 155 of relay T and front contact 154ofrelayJ When a the train passes relay J this relay becomes de=energizedand opens thecircuit for device L at frontcontact 154 ofrelay J At thesame time, relay T isset into operation and vif the speed of the trainis below the predetermined low value, front contact 156 of relay '1closes to move device L to its ineffective 7 position before the trainreaches the device. 7 a 1 1 1 1 y, 7 For purposes of explanation we haveshown and f described our invention applied toa fiv'e-block-signalingsystem} but it should be understood that ourinvention is not limited tothis particulararrangement."

Although we have herein shown anddescribed only two forms of railwaytralfic controlling apparatus embodying ourinvention, it isunderstoodthat variousachan'ges and modificationsmaylbe made thereinwithin the scope ofthe appended claims without departing from the spiritandscope of our invention, 15 of El, Having thus describedour invention,what we claim is: 1; H 1 1. Railway ,tralfic controlling apparatuscomprising train carried mechanism arranged when actuated to cause anapplication pf the brakes, means on the train forpreventmg release ofthe brakes until the expiration of a predetermined time intervalfollowing the last actuation of said'mechanism; and means located 1n thetrackway andopera ing under unsafe tralfic conditions to cause reQpeated actuationsof said mechanism at fiance intervals so short that thetrain win-is;

broughtsubstantially to a stop before the -brakes-can be released. j g 7)2, Railway 'trafiic controlling apparatus comprising train carriedmechanism ar- "ranged when actuated to cause an application of thebrakes, means'on the trainfor preventing release of the brakes until theexpiration of a predetermined time interval following thelast. actuationof said mechanism, and tripping "devices located at intervals along thetrackway and each arranged to actuate saidm'echa'nism when a trainpasses such device "under dangerous traffic conditions, said timeinterval'and the distances be tween said devices beingso related thatafter 'ab'r'ake application has been efiected the brakes can be-releasedonly if the speed of the train is below a predetermined value.

Railway t'raflic. cont-rolling apparatus comprisingtrain carriedmechanism arranged when-"actuated 'to'cause an application of thebrakes, means on the train for preventing release of the brakes untilthe expiration'o f a'predetermined time interval following the last'actuationfof-said mechanism, and'a plurality of tripping deviceslocated at intervals along the trackway and each'effective underdangerous traffic conditions to actuate sa'id mechanism, the "distancesbetween "adjacent ones of saiddevices being less than the distancetraversed during said time interval by a traintravel'ling at more than apredetermined low speed; g

4. In combination, a section ,ofrailway track, a source ofenergyconnected across the rails adjacent one end of the section, an insulatedjoint in one rail of the section, a winding connected across said joint,a slow acting device located in the trackway and controlled bysaid-winding, a'tripping device also located the traclcway andcontrolled in part'by s'aid slow acting device, and train carried govermg means controlled in part by said tii'ppinsnevice. V g

"5,111 combination, a section of railway track, a source of energyconnected with the miisadjacent one end of the section, an n sulate'djoint'lo'cated at anintermediate. point in one rail of the section, awinding connected across said joint, a"slow acting device located at oneenact the section and controlled by saidv Winding, a tripping devlceal's'e-loeated in the trackway and controlled in part by said slowacting device, train car'- ans a'ctiiated'at times by 12f tron 0re 7 6;In'ctifirbinati w v isechaa in, inea-njs located in the trackway for attimes controlling said gavmechanism, a plurality of time measunagdevices having different time eien'iefits and all set into operationwhen a train passes a point a measured distance in rear of said means,and apparatus for controlling said means by a different one of said timemeasuring devices depending on traflic conditions in advance. 7

7. Railway trafiic controlling apparatus comprising train carriedmechanism arranged when actuated to cause an application of the brakes,means on the train for preventing release of the brakes until theexpiration of a predetermined time interval following the last actuationof said mechanism, means located in the trackway for actuating saidmechanism when the train approaches a hazard within the distancerequired for a brake application to bring the train to a stop, and meansfor repeatedly actuating said mechanism as the train approaching suchhazard traverses distances smaller than that which the train couldtraverse in said time interval.

8. In combination with a stretch of railway track, a tripping devicebiased to an effective position and having operating mechanism to movethe device to an ineffective position, a circuit for said operatingmechanism closed only under safe traffic conditions, time measuringmeans set into operation when a train approaching said device passes apredetermined point, means controlled by said time measuring means forat times supplying current to said operating mechanism under unsafetraificvconditionaand train carried overning means controlled by saiddevice.

9. In combination a section of railway track, a tripping device locatedadjacent the exit end of said section, and biased to an effectiveposition, means for holding said device in an ineffective condition whentraffic conditions in advance of said section are safe, a source ofenergy connected across the rails adjacent the exit end of such section,an insulated joint in one rail of said section, a transformer having aprimary connected across said joint, a first relay receiving energy fromthe secondary of said transformer, a slow acting relay controlled bysaid first relay, means controlled by said slow acting relay for attimes moving said device to its ineffective condition when trafficconditions in advance of said section are unsafe, and train carriedgoverning means controlled by said device.

10. In combination, a section of railway track, a-tripping devicelocated adjacent the exit end of said section, and biased to aneffective position, means for holding'said device. in an ineffectivecondition when trafiic conditions in advance of said section are safe, aplurality of normallyopen contacts, means set into operation when atrain approaching saiddevice passes a predetermined point and operating,to close said contacts at the exas the home repeater relay for the nextsection in advance is energized or de-energized respectively providedthe track relays associated with said home relay and with the sectionnext in advance are both energized,

means for energizing each home repeater re lay When the associated homerelay is energized in either direction, a polarized distant relay and adistant repeater relay for each section, means for energizing each saiddis tant relay in the normal or reverse direction according as thedistant repeater relay for the section next in advance is energized ordeenergized respectively provided the home relay for such section inadvance is energized in the normal direction, means for energizing eachdistant repeater relay when the associated distant relay is energized ineither direction, and a signal. for each section controlled by all ofthe associated relays.

12. In combination, a section of railway track, a source of energyconnected across the rails adjacent one end of the section, an insulatedjoint in one rail of the section, a winding connected across said joint,a tripping device located in advance of said joint, a relay receivingenergy from said winding, and means controlled by said relay and bytraffic conditions for controlling said device.

13. In combination, a section of railway track, a tripping deviceadjacent the exit end of said section and normally occupying itseffective condition, means efiective under safe traiiic conditions andoperating when a train is approaching said device to-move the device toits inefiective position provided the speed of said train is below apredetermined value, a second tripping device located at an intermediatepoint in the section, means operating under safe traffic conditions tohold said second device in its ineffective position, and means set intooperation by a train approaching said second device for moving thedevice to its ineffective position provided the speed of such train isbelow a predetermined lower value.

14. Railway traific controlling apparatus comprising a stretch ofrailway track divided into a plurality of successive sections, traincarried mechanism arranged when actuated to cause an application of thebrakes,

means on the train for preventing release of the brakes until theexpiration of a predetermined time interval following the last actuationof said mechanism, apparatus for each section for actuating saidmechanism when a train enters the section under unsafe traflicconditions, said time interval and the lengths of said. sections beingso related that after a brake application has been caused the brakes canbe released only if the speed of the train is below a predeterminedvalue.

In testimony whereof we afiix our signatures.

HAROLD S. LOOMIS. HOWARDA. THOMPSON.

